Coral Acclimation Guide

Bringing new corals into your saltwater aquarium is exciting, but they’re sensitive animals that can easily become stressed or die if moved too quickly. Coral acclimation is the process of slowly adjusting new corals to your tank’s temperature, salinity, light, and water chemistry. Doing this carefully helps your corals open up faster, keep their color, and settle in for long-term health.

Key Points

• Main idea: Go slow and be gentle
  Store water and your tank water are almost never identical. Even small differences in salinity, temperature, or pH can shock a coral. A good acclimation routine reduces this shock by letting the coral adjust gradually over 30–60 minutes before going into your display tank. Think of it as giving the coral time to “catch its breath” between two different environments.
• Tip 1: Float and equalize temperature
  Keep the coral bag sealed and float it in your tank (or sump) for about 15–20 minutes. This brings the bag water to the same temperature as your aquarium, preventing sudden temperature swings. During this time, dim or turn off strong lights to reduce stress when you open the bag.
• Tip 2: Drip acclimate for salinity and chemistry
  After floating, pour the coral and bag water into a small, clean container. Using airline tubing, start a siphon from your tank to the container, tying a loose knot or using a valve to create a slow drip (about 2–4 drops per second). Let the volume in the container roughly double over 20–40 minutes, then gently discard some water and repeat once more if the salinity difference is large. This step helps the coral gradually adjust to your tank’s salinity, pH, and other parameters.
• Tip 3: Dip and place thoughtfully
  Before adding the coral to your tank, use a coral dip (per the product instructions) to reduce pests like flatworms, nudibranchs, and unwanted algae. Rinse the coral in a separate container of clean tank water after dipping. Finally, place the coral low in the tank or in a shaded area first, especially for high‑light tanks or LEDs, and slowly move it to its final position over several days.
• Common mistake to avoid: Rushing and blasting with light
  A frequent beginner error is to take corals straight from the bag, place them high up under intense light, and expect them to thrive. This can cause bleaching, tissue loss, or complete die-off. Always acclimate to light as carefully as you acclimate to water—start lower and shadier, then gradually increase light exposure.

Quick Summary

The most important thing to remember about coral acclimation is to slow everything down: match temperature, slowly blend water, dip for pests, and ease corals into your lighting. A careful 30–60 minutes at the start can mean months or years of healthier, more colorful corals in your reef tank.